Sir Ranulph Fiennes has defended his decision to embark on a perilous winter
crossing of the Antarctic as he returned home after abandoning the attempt
because of frostbite.

The 68-year-old, who may require surgery on two of his fingers, said he was "very frustrated" to have failed, but denied suggestions he had been tempting fate by braving temperatures of minus 70C after suffering from frostbite in the past.

People who have experienced frostbite before are known to be more susceptible to frostbite when they go to extremely cold climates again, though Sir Ranulph said he had been to the top of Everest since his last problem with frostbite without encountering difficulties.

Speaking at Heathrow Airport after arriving on an overnight flight from South Africa, a tired-looking Sir Ranulph said: "I'm no good at crying over spilt milk or split fingers but it's extremely frustrating. I have working on this full-time and unpaid for five years.

"It's unavoidable so I will make the best of it by making my focus entirely on the expedition team, which is going on."

"The vascular surgeon I saw yesterday said that, in his opinion - he wasn't sure - two of the fingers definitely would not require surgery and two of the fingers might require surgery."

Sir Ranulph had been aiming to become the first person to ski from one side of Antarctica to the other in winter, on what he called The Coldest Journey. Other members of the team will carry on with the trip in vehicles, carrying out scientific experiments which will include a search for a bacterium thought to live in the -70C temperatures at the South Pole.

The explorer said "our friends the Norwegians" would probably claim the record now, adding that he still had ambitions for himself, including taking his personal fundraising past the £20 million mark before he dies. He has currently raised more than £15m and had hoped to raise more than £5m for a sight-saving charity, Seeing is Believing, with the planned 2,000-mile Antarctic trek.

He was forced to abandon his attempt when he suffered frostbite in four fingers on his left hand as he took off his outer gloves to fix a ski binding that had come loose at -33C.

He said that the alternative to taking off his gloves would have been to die of cold as he went nowhere, and became defensive when asked if the outcome was predictable given his experience of frostbite 13 years ago, after which he hacked off the tips of his damaged fingers with a fret saw.

He listed a series of expeditions he had completed since then without ill-effect, including three attempts on Everest and a climb on the north face of the Eiger, suggesting they had shown his damaged hand was not a "liability".

He added that last year he had tested some of the equipment in temperatures of -42C, and while a cameraman he was working with suffered frostbite in nine fingers, Sir Ranulph had no problems.

Asked about his next challenge, Sir Ranulph said: "If you start asking what I'm going to be doing after this you would have to talk in the presence of my wife."

Sir Ranulph, regarded as Britain's greatest living explorer, has never allowed health problems to get in the way of his unstoppable appetite for adventure.

He had a heart bypass in 2003 and suffered a heart attack two years later on one of his Everest attempts, but was back on the mountain four years later when he became the oldest Briton to reach the top, aged 65.